I kept getting told that my suggestions will be placed on a list of ToDo's, I know not what position my suggestion is in, nor what else the list contains. Is there a publicly available list of all the features the Pixelmator team are serious about adding to their software, ranked by priority?

Other software companies use UserVoice.com to allow their community to suggest the priority of what they are willing to pay for. Perhaps you wouldn't need to lower the price of your software if customers were able to get what they want, for that they will pay.

We don't have a user vote-based ranking system for our requests — for each request, we also take into account how we personally feel about it and whether it fits in with our vision for each app. With the original Pixelmator, we aren't developing it as actively as Pixelmator Pro and, as I've mentioned, that's because Pixelmator Pro is basically Pixelmator v2, rewritten from the ground up to make it easier for us to add new features. So for that reason, we'll be focusing on smaller and more manageable additions, whereas with Pixelmator Pro, we have a roadmap for the next 6-12 months, so we document user requests and evaluate them in the context of each upcoming update. But in each of those updates, there are usually one or two big features that make it due to popular demand.